Ageing

Ageing can be accelerated and adversely affected by various factors, including:

• UV radiation: strong and prolonged exposure to sunlight can damage the structure of elastomers and plastics and impair their elasticity and functionality.

• Ozone: ozone is a strongly oxidising gas that attacks elastomers and plastics and can cause cracking.

• Weathering: constantly changing and prolonged weather exposure can lead to embrittlement, cracking and loss of sealing performance if the wrong materials are used.

• Temperature: high temperatures at the upper end of, or above, the respective continuous operating temperature range accelerate harmful chemical reactions that can degrade the properties of the material.

• Storage: improper storage, particularly of foamed materials such as cellular rubber and sponge rubber, or of seals with a self-adhesive film on one side, can also accelerate ageing and so impair function and sealing performance, for example through the well-known shrinkage process.

• Embrittlement: the elasticity of the material decreases, which can lead to cracks and fractures.

• Loss of sealing effect: ageing seals lose their ability to seal effectively, for example through a decrease in resilience, which leads to leaks.

• Change in physical properties: ageing can impair the tensile strength, elongation and other physical and mechanical properties of an elastomer or plastic.

Various measures are taken to extend the service life of seals and plastic products:

• Anti-ageing agents: in addition to the various ingredients of a rubber compound, such as fillers, accelerators, additives and plasticisers, specific anti-ageing agents are used to slow down or reduce the ageing caused by the factors described above.

• Storage conditions: storing materials properly in cool, dark and dry places can slow down the ageing process considerably in some cases, particularly for cellular rubber and sponge rubber.

• Material selection: choosing the right material for the specific installation situation and using weather-resistant materials (e.g. EPDM) can significantly slow down the ageing of a seal.

Ageing is a natural process that affects the performance and durability of elastomers and plastics. However, measures such as selecting the right material, using weather-resistant materials and adding anti-ageing agents can slow down and reduce the negative effects of ageing. If you have any questions about ageing resistance or material selection, we are always happy to help.